The melting of Arctic sea ice is causing significant changes to the balance of greenhouse gases in the atmosphere, suggests a new study.
A team of international researchers from Sweden, Denmark, Greenland, Canada and the U.S. studied the melting sea ice in the Arctic region. They observed that a vicious circle is formed when the sea ice melts. Normally, white ice reflects sunlight, which then bounces back into space. But when the sea ice shrinks, it causes a significant reduction in the amount of sunlight reflected back into space. A large portion of sunlight is absorbed by the surface of the ocean which causes warming. This, in turn, contributes to the rise in air temperatures around the Arctic.
The rising temperatures have both positive and negative effects on the climate. On one hand, the temperature rise makes vegetation grow more vigorously. In this process more carbon dioxide is absorbed, which has a positive effect on the climate. On the other hand, the temperature rise leads to the release of methane and carbon dioxide from the soil. This has a negative impact on the climate.
The melting of sea ice not only contributes to significant changes on the land, it also has a tangible impact on the amount of greenhouse gases exchanged through natural processes, the researchers concluded.
"Changes in the balance of greenhouse gases can have major consequences because, globally, plants and the oceans absorb around half of the carbon dioxide that humans release into the air through the use of fossil fuels. If the Arctic component of this buffer changes, so will the amount of greenhouse gases in the atmosphere," one of the study authors Frans-Jan Parmentier, a researcher at Lund University, Sweden, said in a statement.
The findings of the study are published in the journal Nature Climate Change.